INTRODUCTION. 47 



these are not concealed as in the Papiliones, but project beyond the head : the third 

 joint distinctly appears, not naked as in the Vermiform stirps, but closely covered 

 with down. The basal and the second joints are generally broad and robust^ they 

 are covered with hair on all sides and are likewise beset underneath with long strag- 

 gling bristles, which give them that peculiar roughness, which in these organs is 

 characteristic of the stirps. In the typical species the third joints converge or are 

 bent towards each other, from each side, forming, in the language of Latreille a 

 rostellum. Near the extremity of the second joint, stands, in most cases, a tuft 

 of lengthened hair, which gives the extremity of the palpi, in a lateral view, a 

 forked appearance. This character exists in different degrees of development, in 

 the subdivisions of the stirps. I refer for illustration of it provisionally to the 96th 

 plate of Curtis's British Entomology, until the dissections shall have been given in 

 the progress of this work. 



The antenna; of this stirps are of moderate length and filiform at the base, with 

 a club rising abruptly, near the extremity, which, in the typical species is broad 

 and compressed. In Argynnis it is nearly orbiculate, and has been compared with a 

 target or shield. In the sub-divisions which recede from the typical groups and 

 approach to the fourth stirps, the club, although still terminal, is very gradually 

 capitate or swelled. 



The gradual change of character which takes place in the metamorphosis of the 

 second stirps as it approaches the confines of the third, has already been indicated : 

 the transition is confirmed by the structure of the anterior feet. Several of the 

 subjects which have been enumerated as situated near the union of the two stirpes, 

 have an intermediate character, which is illustrated on the third plate : I refer to 

 fiV. 29, d. and 28, d, the former exhibiting the anterior feet of Heliconia, the latter of 

 Idea. In both, these organs are abbreviated towards the extremity : the tarsi are 

 not distinguishable into five joints, but are united, and their situation is indicated by 

 several spines which are crowded together. But on entering the stirps fully, we 

 find the anterior feet, in both sexes, constructed on a different plan. They are not, 

 as in Colias, and in several genera of the Vermiform stirps. partially reduced in size ; 

 but they are spurious and imperfect. Both the femur and the tibia are of slender 

 dimensions, and the tarsus consists of a single member, which in the typical genera 

 possesses neither joints nor claws : they are moreover very hairy, and have been 

 compared to a tippet. Latreille, in his general remarks on this order, describes 

 them thus : Pedes antici submutici, interdum hirsutissimi, inflexi, pectori adpressi, 

 inde spicrii. The intermediate and posterior feet, in the typical group, are termi- 

 nated by claws and pulvilli with membranaceous pubescent bifid appendages at their 

 base. See Curtis's Br. Entom., plate %. 



The 



